Which Carb Gives a Balance of Power & MPG?

I've had a similar talk with the owner of an old time carb shop here in detroit. I was debating about sticking with the carter AFB on my 360 or going with a new eddy or holley. He said that a properly tuned original carter AFB is about the best carb you could ask for. He also said that the old AFBs are better than the new eddys. Another bonus is you can get a used AFB or AVS and rebuild it (jetted for YOUR engine) for less than an eddy or holley or whatever.
I do trust this guy, he really knows carbs